Electron mobility and physical magnetoresistance in n-type GaSb layers grown by molecular beam epitaxy

Electron mobility and low-field transverse physical magnetoresistance were measured in Te-doped GaSb layers grown by molecular beam epitaxy. The samples investigated had electron densities ranging from to ; measurements were taken in the 8 - 300 K temperature range. The high mobility values demonstrate that SnTe can be used as a source of Te doping with results comparable with GaTe. A detailed analysis of the magnetoresistance data demonstrates that in samples with high electron density the magnetoresistance is mainly due to mixed conduction of electrons in both and L conduction band minima: the analysis gives the temperature dependence of the and mobilities and of the energy separation between L and edges. is 82 meV at 300 K and 67 meV at 8 K and exhibits a non-monotonic behaviour within the temperature range explored. In samples with low electron density the magnetoresistance is mainly due to the energy distribution of carriers in the valley.